Pest control device

ABSTRACT

PCT No. PCT/EP95/02701 Sec. 371 Date Jan. 16, 1997 Sec. 102(e) Date Jan. 16, 1997 PCT Filed Jul. 7, 1995 PCT Pub. No. WO96/02134 PCT Pub. Date Feb. 1, 1996A device for controlling crawling pests comprising a tunnel in which the ceiling is treated with a pest control agent and the gap between floor and ceiling in the treated area decreases from at least one edge of the treated area. A pest entering the device receives a topical dose of the pesticide control agent on its upper parts.

The present invention relates to the control of crawling pests, e.g.,crawling insects, arachnids, wood lice, millipedes and centipedes, butespecially cockroaches. More particularly the invention is concernedwith a localized placement device for the control of such pests.

PRIOR ART

Crawling pests have conventionally been controlled by applying a pestcontrol agent to an area, usually by spraying, so that when the targetpest crawls over that area it acquires a lethal dose of the agent.However, in this method, humans and non-target creatures can contact thepest control agent, and contamination of foodstuffs or surfaces mayoccur which could be harmful. Furthermore, the target pest may not stayon a treated area long enough in order to acquire a lethal dose, andthis may result in the development of repellency, or resistance, to theagent concerned.

U.S. Pat. No. 4,970,822 describes a contact poison delivery system forcockroaches comprising a tunnel structure having two vertical walls andtwo horizontal walls defining a poison containment area. An insecticideis applied to the internal horizontal surfaces so that a cockroachwalking through the tunnel and contacting those surfaces receives a doseof insecticide. However, the embodiments described are suitable only forthe control of cockroaches of a particular size, and we have found thatthe construction of the device does not allow the insecticide to betransferred even to an insect of appropriate size in a particularlyefficient manner. In addition, insecticide is transferred to the legsand feet of the cockroach, and some of this will naturally be depositedon any surface or foodstuffs that it subsequently crosses, resulting inundesirable further contamination. Such contamination is likely to be atsub-lethal levels and, if encountered by other pests, might contributeto the development of resistance. In the region of the device, it couldalso act to repel further pests from entering the device.

DESCRIPTION

The present invention provides a localised placement device for thecontrol of crawling pests, particularly insects, and especiallycockroaches, which reduces or overcomes some of the disadvantages of theprior art.

In one aspect, the present invention provides a device for the controlof crawling pests, said device comprising a tunnel into which a crawlingpest may enter, characterised in that the interior surface of the tunnelceiling, or a portion thereof, is treated with a suitable pest controlagent, and in that the gap between floor and ceiling in the treated areadecreases from at least one edge of the treated area; such that a pestentering the device may encounter said decreasing gap and receive uponcontact with the treated surface a dose of the agent topically on itsupper parts.

Where the target pest is an insect, the dose is received topically onits antennae, dorsal surfaces of the thorax, abdomen or head.

The floor of the tunnel is preferably formed from a thin layer of amaterial that does not represent a significant barrier for the pests tocross and enter the device.

The floor of the tunnel is preferably flat, in which case the treatedarea of the ceiling desirably slopes from opposite edges towards thefloor in the direction of the interior of the device to provide thereduction in the floor-to-ceiling gap. For the control of most crawlinginsects, especially cockroaches, the floor-to-ceiling gap preferablydecreases from about 10 mm to about 2 mm, desirably towards the interiorof the device. This could alternatively be achieved by means of a flatceiling and a sloping floor, but this presents a change in environmentthat is detectable by and may therefore deter the target pests. When asloping ceiling is used, the change in environment is only detected oncethe ceiling has been contacted, i.e., once the dose of the pest controlagent has been transferred.

In comparison with a device in which the floor and ceiling are parallel,the reducing floor-to-ceiling gap enables a far wider range of sizes ofcrawling pest to be accommodated and controlled. In addition, itexploits the inherent investigative nature of certain pests, especiallycockroaches, which have a propensity to explore small gaps and crevices.To encourage such behavior, and thus increase the contact between thepest and the treated area, at least a small floor-to-ceiling gap ispreferably maintained over all or substantially all of the treated area.

A path may be provided for the pest to enter the device at one end andexit at the other, having contacted the treated portion, but this is notessential. Such a path may be imposed on the pest by means of one-waydevices at suitable points, particularly one-way entrance and exitdoors.

The device of the present invention is not a harbourage or trap, andindividual pests generally remain in it for a very short time, typicallyless than 5 seconds, leaving to die remote from the device once contactwith the pest control agent has occurred. In this way the pest controlagent may with further advantage be transferred back to the pests'natural harborage or to other pests. Although there may be aconsequential transfer of the pest control agent to the environment,this will generally be less than that from known devices in whichapplication is made to the feet or legs.

The tunnel entrance is preferably rectangular in cross-section.

The ceiling is preferably convex. It is also preferably deformable ormovable on contact by the target pest, thereby improving or prolongingthe contact between the pest and the pest control agent. To this end, acompressible padding material may be located between the interior andexterior surfaces of the ceiling adjacent to the movable/deformablesurface. Alternatively, the compressible padding may be replaced by asupporting structure that gives some flexibility to the treated portionof the ceiling. In another embodiment, the treated portion may be alight, deformable, movable structure that is suspended from the ceiling,and is not in contact with the floor of the device.

In a further form of construction, contact with the ceiling, or astructure suspended from it, by the target pest may be made to act as atrigger for a second mechanism to dose the insect.

The treated interior ceiling of the device is desirably removable toenable it to be replenished with pest control agent or replaced.

User exposure to the pest control agent may be limited by the devicefurther comprising, at both ends of the tunnel, a portion of theinterior surface of the ceiling which is not treated with the agent.Alternatively, the device may be provided with suitable baffles at eachentrance, which should not of course significantly obstruct the targetpests from entering the device.

The construction of the device is preferably such that two or more maybe linked to form a modular structure.

The device may also beneficially incorporate features attractive to thetarget pest, for example a dark interior, which has the added advantageof allowing photolabile compounds to be employed which may be ofenhanced activity. In addition, the device may of course containpheromones or foodstuffs.

The pest control agent is preferably applied to the tunnel ceiling in a1-500 μm thick film of a suitable formulation. The formulation itself isdesirably such that it adheres to the tunnel ceiling without soakinginto, migrating on, or dripping from it, does not flow at rest, isphysically and chemically stable for several months under the conditionsof use, and becomes flowable under small shear stress so as to bereadily and consistently transferred to the upper surface of the pestwhilst rapidly regaining its original structure and viscosity underno-shear conditions. The amount of formulation transferred in thecontact is preferably adequate to provide a lethal dose on singlecontact, but small enough that sufficient remains to ensure the devicecontinues to be effective against further pests. In addition, theformulation should not be repellent to the target pests.

Formulations which may exhibit these properties are typically greases,pastes, gels or creams, and will most frequently comprise one or morepest control agents, optionally a synergist, a gelling/structuringagent, and one or more thickeners, stabilizers, solvents and cosolvents.

The pest control agent may for example be an insecticide, sterilizingagent, growth regulator, juvenile hormone analogue or behavior modifier.Particularly preferred are the synthetic pyrethroid insecticides, e.g.,acrinathrin, allethrin (such as D-allethrin), benfluthrin, bifenthrin,bioallethrin, S-bioallethrin, esbiothrin, esbiol, bioresmethrin,cycloprothrin, cyfluthrin, beta-cyfluthrin, cyhalothrin,lambda-cyhalothrin, cypermethrin, alpha-cypermethrin, beta-cypermethrin,cyphenothrin, deltamethrin, empenthrin, esfenvalerate, fenpropathrin,fenvalerate, flucythrinate, tau-fluvalinate, kadethrin, permethrin,phenothrin, prallethrin, imiprothrin, resmethrin, tefluthrin,tetramethrin or tralomethrin. Among these compounds deltamethrin isespecially useful.

The activity of the insecticide may be enhanced by the addition of asynergist or potentiator, for example one of the oxidase inhibitor classof synergists such as piperonyl butoxide or propyl 2-propynylphenylphosphonate.

The gelling/structuring agent can be a bentonite, a modified clay orsilica, such as BARAGEL 3000 from Redland Minerals Ltd., zinc stearateor any mixture of a salt and a surfactant able to produce a gel.

The viscosity of the formulation, under no-shear conditions, ispreferably greater than or equal to 15,000 mPa secs at a temperaturebetween 10 and 35° C. On contact with a pest, the formulations shouldpreferably shear to a viscosity of no less than about 1000 mPa sec.

The thickener, an ingredient able to increase the viscosity of theproduct, typically consists of a hydrocarbon wax with more than 18carbons length and soluble in the vehicle i.e., the liquid phase made bythe solvents and co-solvents; an example of such an ingredient isLUNACERA MW from Industrial Waxes Limited.

The solvent or vehicle preferably has a boiling range greater than 280°C at atmospheric pressure, e.g., a mineral white oil such as ONDINA 15,a heavy hydrocarbon solvent such as BVA XK3, a vegetable oil,hydrogenated or methylated or not modified, MIGLYOL oils like 812N.Solvents or vehicles without odor and repellent effect are preferable.

Co-solvents can be used to help solubilization of the active ingredientand can be, for example, selected from ketones, glycol ethers, andglycol esters.

Stabilizers when necessary are selected from anti-oxidants such as BHT,BHA, propyl-gallate, and acidifying agents like citric acid, acetic acidor salts from the dodecylbenzene sulfonic acids.

Preferred formulations for use in the device of the present inventioncomprise:

    ______________________________________                                                         % w/w                                                        ______________________________________                                        Active ingredient (insecticide)                                                                  0.01-80                                                      Gelling/structuring agent 0.00-30                                             Thickener 0.00-30                                                             Stabilizers 0.00-10                                                           Solvents 10.00-80                                                           ______________________________________                                    

Where the active ingredient is deltamethrin, its content in theformulation is preferably from 0.01 to 30% w/w preferably 1 to 10%, andmore particularly 2 to 7% w/w.

A specific preferred formulation may be prepared from the followingingredients:

    ______________________________________                                                        % w/w                                                         ______________________________________                                        Deltamethrin      5                                                             MIGLYOL 812 N 63.9                                                            Citric acid 0.1                                                               Calcium Phenylsulfonate 1                                                     LUNACERA MW 20                                                                BARAGEL 3000 10                                                             ______________________________________                                    

by solubilizing the deltamethrin in the MIGLYOL 812 N with the LUNACERAMW, citric acid and calcium dodecylbenzene sulfonate by stirring at atemperature of 70° C., then dispersing the BARAGEL 3000 using a highshear mixer to obtain a gel having a viscosity around 15,000 mPas at 20°C. and over 500 mPas at 50° C.

The present invention also provides a method for the control of crawlingpests, particularly insects, in a specified area by placing one or moreof the localized placement devices of the present invention in theinfested area, for example domestic house kitchens, restaurant kitchensor food preparation areas.

EXAMPLES

In a non-limiting manner, preferred embodiments of the device of thepresent invention will now be described with reference to theaccompanying drawings in which:

FIG. 1a is a cross-sectional side view of a preferred device accordingto the present invention.

FIG. 1b is a diagrammatic partly cut-away perspective view of the deviceof FIG. 1a.

FIG. 2a, 2b and 2c illustrate perspective views of the device of FIGS.1a and 1b in use in various orientations.

FIG. 3 illustrates schematically the procedure for the insertion andremoval of the refill portion of the device of FIGS. 1a and 1b.

FIG. 4 is a diagrammatic perspective view of a simple localisedtreatment device according to the invention.

FIG. 5 is a schematic view of the structure of the interior ceiling ofthe device of FIG. 4.

FIG. 6 is a diagrammatic perspective view of a simple localizedtreatment device according to the invention.

In FIGS. 1a and 1b, a plastic casing (1) forms the walls, roof and baseof the device. In use, the device contains within it a refill body (2)formed of plastics material e.g., polypropylene, this refill body beingremovable to enable its replacement. Locking means (3) engage the twoportions of the casing on closure. A simple key pushed into the openings(9) enables the device to be opened. The refill body comprises adeformable substrate (4) of a foam material, which forms the ceilingsection of the interior of the device and provides the necessaryreduction in the floor-to-ceiling distance. The foam material may alsobe covered with a thin layer of plastics material, e.g., polypropylene.The surface of the substrate (4) is coated with an insecticidal paste(5). In alternative embodiments, the refill body merely comprises asolid curved structure of plastics material, preferably polypropylene,and the surface is coated with the insect control agent. In theembodiment shown, the refill body also has a region (6) adapted toreceive a tablet (7) of attractant to the target insect. Theentrance/exit regions of the device incorporate baffles (8) which formmaze sections (10). Such sections minimize user accessibility to thetreated refill body while providing a minimal barrier to movement of theinsect into the device. Ganging fixings (11) and (12) are shown on theexternal side walls of the device.

In use, the target insect enters the device in the direction of thearrow shown in FIG. 1b. The sloping ceiling allows for contact bydifferent development stages of the target insect and also permits theinsects to progress further into the device until contact with theceiling and resultant transfer of the insecticide occurs. The smallestdevelopment stages of the target insect and also some adults may be ableto pass through the device, contacting the treated portion where thefloor-to-ceiling distance is at its minimum.

In FIGS. 2a and 2b, the positioning of a device of FIGS. 1a and 1b isillustrated, in a horizontal position and a vertical positionrespectively. The device is held in the vertical orientation by means ofadhesive pads. These are also preferably used for a horizontalpositioning to prevent the device from being inadvertently moved. FIG.2c illustrates the use of several devices fixed together by means ofmale and female fixings (11) and (12) respectively, thus increasing theoverall catchment area.

FIG. 3 illustrates the simple procedure for loading the refill body intothe device and also for unloading the refill body.

In FIG. 4, typical dimensions of the device for the control of theGerman cockroach (Blattella germanica) are: a=10.5 cm, b=5 cm, h=0.8 cm,a1=12 cm, b1=6 cm but these dimensions may vary with the species andbehavior of the target pest. A solid plastic casing (1) forms the wallsand the roof of the device, which is fixed on a cardboard base (13). Theinterior ceiling (14) has a convex interior surface (15) such that theheight between it and the cardboard base is about 0.7 centimeter at theentrance and the exit of the device (c), and about 0.2-0.3 centimeter atthe center inside the device (d).

In FIG. 5, the interior ceiling (14) of FIG. 4, consists of a convexaluminium foil (16), where the exterior surface is the interior surfaceof the ceiling (15), which foil covers a cotton wool pad (17) locatedbetween (16) and a plastic backing (18). Structure (14) is fixed to theinterior surface of the roof of the device.

In FIG. 6, the interior ceiling (15) consists of aluminium foil theconvex shape of which is provided by fixing the foil over dental rolls(19) fixed on a cardboard base (20), to provide a specific minimumfloor-to-ceiling distance within the tunnel. The ceiling is, however,unsupported between the edge of the roof and the lowest point. FIG. 6also shows the treated surface (5). The dimensions of this device usedfor controlling Blattella germanica, are preferably of the order: i=1.7cm, j=k=10 cm, m≧0.2 cm.

Activity Example

In laboratory tests, a single device according to the inventioncontaining 0.3 g of a 5% w/w deltamethrin paste caused 100% kill ofadult Blattella germanica, Blatta orientalis and Periplaneta americanacockroaches, from the susceptible laboratory strains, in a 1.1×1.1 marena that contained harborage, food and water. Under identicalconditions, using a strain of Blattella germanica which was 20 timesmore resistant to deltamethrin, 94% males and 50% females were killedovernight. In three dimensional (2.5×2.5×2 m) arenas, with food, waterand harborage, two devices caused a 50% reduction (100% males, 70%females and 30% nymphs) of a mixed age population of the susceptibleBlattella germanica strain within 72 hours.

In field trials at two locations in an infested kitchen area, localizedplacement devices of the present invention, containing 0.3 g of a 5% w/wdeltamethrin paste formulation reduced the Blattella germanicapopulation by 60-95% after one week. The cockroach population was morethan 20 times more resistant to deltamethrin than the laboratory strain.

I claim:
 1. A device for the control of crawling pests, said devicecomprising:a tunnel into which a crawling pest may enter, the tunnelhaving a floor, a ceiling and a gap between the floor and the ceiling,at least a portion of an interior surface of the tunnel ceiling treatedwith a suitable pest control agent, wherein the gap between floor andceiling in a treated area progressively decreases in the direction ofcrawl; such that a pest entering the device may encounter said treatedsurface of said ceiling as a result of crawling into said progressivelydecreasing gap and receive upon contact with the treated surface a doseof the agent topically on the pest's upper parts.
 2. A device accordingto claim 1 in which the floor of the tunnel is flat.
 3. A deviceaccording to claim 2 in which at least a small floor-to-ceiling gap ismaintained over substantially all of the treated area.
 4. A deviceaccording to claim 2 in which the ceiling is convex.
 5. A deviceaccording to claim 2 in which the ceiling is movable upon contact withthe target pest.
 6. A device according to claim 5 in which acompressible padding material is located between the interior andexterior surfaces of the ceiling adjacent to the movable surface.
 7. Adevice according to claim 2 which, in order to limit user exposure tothe pest control agent further comprises, at both ends of the tunnel, aportion of the interior surface of the ceiling which is not treated withthe pest control agent.
 8. A device according to claim 2 which furthercomprises baffles at each entrance which do not obstruct target pestsentering the device.
 9. A device according to claim 8 in which at leasta small floor-to-ceiling gap is maintained over substantially all of thetreated area, the ceiling is convex and movable on contact with thetarget pest and at both ends of the tunnel, a portion of the interiorsurface of the ceiling is free of the pest control agent.
 10. A deviceaccording to claim 9 in which a compressible padding material is locatedbetween the interior and exterior surfaces of the ceiling adjacent tothe movable surface.
 11. A device according to claim 10 in which thetreated portion is a light, deformable, movable structure that issuspended from the ceiling, and is not in contact with the floor of thedevice.
 12. A device according to claim 9 in which the gap decreasesfrom about 10 mm to about 2 mm.
 13. A device according to claim 1 inwhich at least a small floor-to-ceiling gap is maintained oversubstantially all of the treated area.
 14. A device according to claim 1suitable for crawling insect control in which the gap decreases fromabout 10 mm to about 2 mm.
 15. A device according to claim 1 in whichthe ceiling is convex.
 16. A device according to claim 1 in which theceiling is movable upon contact with the target pest.
 17. A deviceaccording to claim 16 in which a compressible padding material islocated between the interior and exterior surfaces of the ceilingadjacent to the movable surface.
 18. A device according to claim 16 inwhich the treated portion is a light, deformable, movable structure thatis suspended from the ceiling, and is not in contact with the floor ofthe device.
 19. A device according to claim 1 which, in order to limituser exposure to the pest control agent further comprises, at both endsof the tunnel, a portion of the interior surface of the ceiling which isnot treated with the pest control agent.
 20. A device according to claim1, wherein the portion of the interior surface of the tunnel ceiling istreated with the pest control agent such that the pest entering thedevice and encountering said decreasing gap receives upon contact withthe treated surface a dose of the agent topically only on the pest'supper parts.
 21. A device according to claim 1, wherein the tunnel isdeveloped for localized pest-control placement within a human household.22. A device according to claim 1, wherein the tunnel is developed forlinking to form interconnected, modular tunnel structures.
 23. A deviceaccording to claim 1, wherein the treated area is developed in the formof a replaceable refill body.
 24. A device according to claim 23,wherein the tunnel comprises a section providing access to the interiorof the tunnel for replacement of the refill body.
 25. A device accordingto claim 1, wherein the pest control agent is applied to the treatedarea in the form of a film.
 26. A device according to claim 1, whereinthe pest control agent is applied to the treated area in a form selectedfrom the group consisting of liquids, pastes, gels, and waxes.
 27. Adevice according to claim 1, wherein the pest is dosed by direct contactbetween the pest control agent and the pest.
 28. A device according toclaim 1, wherein the gap decreases gradually in a direction along thelength of the tunnel.
 29. A device according to claim 1, wherein thepest control agent adheres to the tunnel ceiling and becomes flowableunder a small shear stress provided directly by the pest's upper parts.30. A device for control of crawling pests, the device comprising:atunnel for localized placement in a human household and into which acrawling pest may enter, the tunnel having a floor, a ceiling, and a gapbetween the floor and the ceiling; and means for dosing a pest, themeans for dosing being disposed adjacent the ceiling and treated with asuitable pest control agent, the means for dosing being developed so asto progressively restrict the size of the gap between the floor and theceiling, such that a pest moving within the tunnel may encounter themeans for dosing by crawling into a restricted portion of the gap and bedosed with the pest control agent topically on the pest's upper parts.31. A device according to claim 30, wherein the pest control agentadheres to the tunnel ceiling and becomes flowable under a small shearstress provided directly by the pest's upper parts.
 32. A deviceaccording to claim 30, wherein the tunnel is adapted for placement onhorizonal and vertical surfaces.